1. Field of the Invention
Embodiments of the present invention relate to a multi-user Multiple Input Multiple Output (MU-MIMO) communication scheme.
2. Description of the Related Art
A wireless communication system uses a multi-antenna Multiple Input Multiple Output (MIMO) communication scheme to enhance a frequency efficiency of radio resources. For example, the multi-antenna MIMO communication scheme may use a codebook-based multi-antenna MIMO communication scheme.
In the codebook-based multi-antenna MIMO communication, a terminal may select, as a precoding vector, at least one column vector from a plurality of column vectors included in a precoding matrix, and may feed back information associated with the selected precoding vector to a base station. The base station may have the same codebook as a codebook of the terminal. The base station may identify the precoding vector selected by the terminal, based on the fed back information associated with the precoding vector. The base station may transmit data to the terminal using the identified precoding vector.
A particular precoding vector may concentrate transmission energy in a particular direction. Accordingly, when different terminals receive data using the same precoding vector, a data transmission performance may be deteriorated due to interference between the terminals.
The base station may need to select only a single terminal from a plurality of terminals having selected the same column vector as the precoding vector, and to transmit data to the selected terminal.
Accordingly, each of the terminals may select a different column vector as the precoding vector to enhance the data transmission performance.